The effect of the late severe winter being now, in some measure, apparent, it may not be amiss to compare its effects in different localities. We can hardly account for the effect produced on trees and plants here, from the degree of cold indicated by the thermometer, unless we allow something for the long continuation of the cold weather. No thermometer was seen, in this locality, lower than 13° below zero; mine was seen only at .8° below. But I cannot help thinking they have been lower than this. Soon after New Year's day, the wind blew for several days from the northwest, and was very cold; the morning of the 7th, my thermometer was 2° below zero, at sunrise, but, I may observe that, as my situation is much sheltered from the west, the thermometer here does not fall as low as at other places in the neighborhood. On the morning of the 9th, it was again 2° below, and did not rise, during the day, to more than about 15° above. The wind having ceased blowing from the northwest, it began, about noon, to blow from the south, and continued about 24 hours to blow moderately from that quarter.

A southerly wind following a cold one from the northwest, is always, for the first 12 hours, more piercing and unpleasant than the other, being accompanied with a moisture in the atmosphere that makes it exceedingly unpleasant; but, if con-tinned more than that length of time, it always becomes warmer. So, in this case, when the south wind began, the thermometer was about 15° at noon; at sundown it was at zero, at 8 o'clock, at night, 5° below, and, next morning, again at zero. One of my neighbors says his was 13° below at 7 o'clock P. M., so that I cannot help suspecting that the thermometers were lower, during that night, than any of us were aware of.

The peach buds, in many places, are much injured, particularly in valleys and low grounds, while, on high lands, they are uninjured. In my orchard, the more tender varieties are generally destroyed, particularly in the lower part of it. Higher up, the more prominent buds are killed, while a few of the apparently weather buds are now pushing out into bloom. On still higher ground, they are still less injured, but, even there, many buds are dead.

I have a Deodar Cedar, full twelve feet high and twelve inches in circumference at the base, and well branched from the ground, that last fall was a beautiful object, but now presents a sorrowful appearance. All the leaves, with very few exceptions, above the snow line are dead, and the branches look so, too. The lower branches near the ground being covered up with the snow, are not injured, and are now pushing out young buds. The bark and wood beneath looks dark, as if killed, but whether the larger limbs will put out leaves or not, remains to be seen; the smaller twigs are certainly dead. A few green leaves still remain a few feet from the top, near the main stem. This tree was planted, I believe, in 1851, and survived the winters of 1851,1852, and last winter, except a few of the extremities of the branches.

A Japan Cedar, ten feet high, that was planted out in 1852, has survived the past winter with but little injury; a few of the extremities of the small branches of last year's growth only are killed, and the tree now looks in good condition. It stands on ground about fifteen feet higher than the Deodar; otherwise I know of no difference in situation. This would indicate the Japan Cedar to be more hardy than the Deodar, while the reverse was supposed to be the fact; and, if experience should elsewhere confirm this instance, it would give additional value to the Japan Cedar. The Himalaya Spruce and Menzies Spruce both have lost some leaves, and the latter some small shoots. Irish Yew suffered severely; two specimens were killed down to the snow line, and the third, on higher ground, lost all its outer leaves; the Ivy, too, lost all its outer leaves. Most of our rose bushes were killed above the snow, even when they were inclosed in straw, while those that were laid on the ground and covered up have come out in fine condition. The Evergreen Honeysuckle was killed down to the roots. Paulowonia Imperialis has suffered in its flower buds, and its leaf buds look as if injured, while the bark of the branches looks well.

The Pride of India has often its extreme shoots killed for a few inches, but now it appears more hurt- - time will only show to what extent B. Hodge, of Buffalo, asks for the experience of peach growers in other sections, in regard to the effect of extreme cold weather on peach-trees. In answer, I will relate occurrences that took place here more than twenty years ago. On the morning of the 5th of 1st month (Jan.), 1835, the mercury in the thermometer fell to from 18° to 20° below zero in this part of the country. The consequence was, the peach buds were killed, except on our mountain ranges, and the trees themselves looked dark beneath the bark, and many supposed them killed, and some were actually cut down. But, as spring opened, it was found that only the small branches of less than about the size of one's finger, were actually dead, while the larger branches put out shoots, though late, and grew finely, and a new layer of wood was deposited beneath the bark, and covered up the dark wood.

This dark wood was risible for a number of years after; and after a time began to decay, while the outside wood was sound. This effect is still risible in our old trees, being decayed inside while still bearing fruit. Trees often lire here to be thirty years old, and I am not sure that it injured their bearing afterwards, though, by causing' the larger branches to be weaker, they were more liable to be broken down when loaded with fruit We find the Grosse Mignone here our most tender variety.

It was rather remarkable, that the cold was more intense across the middle of this State, this winter, than on its northern border, the thermometers, in some places, indicating 26° below zero, and the ice at Fredericksburg, on the Rappahannock, was said to hare been twenty-fire inches thick.

In several numbers of the Horticulturist lately, there hare been articles commending the Lombardy Poplar as an ornamental tree. That it has its peculiarities, which render it particularly desirable in certain situations, none can doubt; but all through this region it has died outright, and I know not of a single thrifty specimen anywhere. What can be the cause of so general a destruction? This might be worth while for arboriculturists to inquire into. One suggestion that has been made is, that as the plant is dioecious, and as we hare had only the fit a mi* nate variety, and, consequently, no reproduction from seed, this may be the cause of their failure. If this should be the fact, it might be an easy matter to introduce both kinds from their natire regions, and again be able to disseminate them, I hare noticed quite a number of plans recommended as specifics against the depredations of insects on young plants, particularly young cucumbers. The best remedy I hare ever seen tried is a decoction of Quassia, say one pound to two gallons of water, boiled so as to get its strength, then, with a small sprinkler or watering-pot, wet the plants well all over, by turning up the under side of the leaves, and, if this is carefully done, no insects will injure them; as new leaves push ont, or when rains wash the plants, a repetition will be needed, Quassia can be obtained at the wholesale apothecaries, at about sixteen cents per pound, and its bitter principle seems peculiarly distasteful to insects.

A desire to benefit my brother horticulturists, is my excuse for bo many different subjects in one communication.

May 1,858.